(1) Field of the Invention
This invention relates, broadly speaking, to novel liquid crystal displays.
More particularly, this invention relates to novel liquid crystal color modulation displays and operating electronic circuitry capable of exhibiting colors over a range of colors, which colors can be changed as desired within said range to create novel aesthetic effects. Said liquid crystal color modulation displays can, for example, be embodied in a cell construction, such as a flexible plastic cell, which in turn can be secured by any suitable means to objects such as articles of clothing, watches, automobiles, furniture, walls and the like.
(2) Description of the Prior Art
Liquid crystal displays, used for example in watches and television screens, are well known in the art.
"Field-Induced Color Switching in Liquid Crystal Displays," M. Schadt, J.Chem.Phys. 71(6), Sept. 15, 1979, pp. 2336-2344, discloses a liquid crystal guest-host effect which modulates color intensity, and its color changes upon the application of a voltage.
U.S. Pat. No. 4,702,561 (1987) discloses a guest-host display with pleochroic dyes, containing negative and positive order dyes to produce a change of color from one to another.
U.S Pat. No. 3,833,287 (1974) discloses a thin film liquid crystal device employing the guest-host principle, in which unpolarized light is selectively absorbed. In the absence of an electrical field across the thin film, virtually all the unpolarized light is absorbed by the film. When an electric field is applied to the film, none of the unpolarized light is absorbed. This device can be used for displays.
U.S. Pat. No. 4,759,611 discloses a flexible plastic cell enclosing guest-host material in which the color can be changed according to applied voltage. An oscillator control circuit changes the color at the desired frequency.
U.S. Pat. Nos. 4,834,508 (1989), 4,878,741 (1989) and 4,953,953 (1990) each discloses a liquid crystal cell acting as a color filter and used in information displays.
U.S. Pat. No. 4,390,245 (1983) discloses an optical display cell comprising liquid crystal material held within spaced substrates. Spacers are provided between the substrates to maintain a uniform distance therebetween.
U.K. Patent No. 2,138,838 (1984) discloses a guest-host liquid crystal material having a dye with a negative order parameter which goes from colorless to color under applied voltage.
U.S. Pat. Nos. 4,624,531 (1986) discloses a guest-host display to produce colored symbols on a colorless background.
U.S. Pat. No. 5,026,505 (1991) discloses a guest-host display.
U.S. Pat. No. 4,838,659 (1989) discloses a guest-host display using fluorescent dyes. The guest-host display modulates the color and the fluorescense of the dye.
U.S. Pat. No. 4,957,350 (1990) discloses a liquid crystal display device that uses red, green and blue striped cells serving as color filters.
U.S. Pat. No. 5,015,074 (1991) discloses a display device filled with different dyes in a liquid crystal host.
U.S. Pat. No. 4,630,894 (1986) discloses a multi-colored liquid crystal display with a color transreflector and color filter.
U.S. Pat. No. 4,922,239 (1990) discloses a multi-shade color liquid crystal display apparatus using several color filters to produce shading variations of one color.
U.S. Pat. No. 4,664,479 (1987) discloses the use of a guest-host material to turn a mirror into a non-reflective display.
U.S. Pat. No. 4,935,160 (1990) discloses a liquid crystal guest-host system employing several pleochroic dyes, and is designed for informational display using different layers of the guest-host mixtures.
U.S. Pat. Nos. 4,707,080 (1987), 4,616,903 (1986), 4,556,289 (1986), 4,506,956 (1985), 4,886,343 (1989), 4,601,547 (1986) and 4,737,610 (1988) disclose various liquid crystal displays.